This one is a bit rough to explain- and it requires explaining alot about how Tritium and atmospherics in general works.
Firstly - Atmospherics has 2 very important cvars (constant variables, which are basically a giant list of hard-coded values used in various places across the entire game and multiple files and which are configurable by the server)
One is AtmosSpeedup, which artificially speeds up the "rate" of all atmospheric devices flowrates - that is, anything that is a pump.
The other is HeatScale, which is the same value (though they can be independently configured, they are always the same on every server I know of), that is used for various purposes but whenever it is used it will reduce the heat capacity of a given mixture of gas to a fraction of the HeatScale. (So if Heatscale is 8, then when used it makes heat capacities 1/8th their "true" value).
As for why we have these - I don't know, couldn't tell ya.
The one we are concerned with for this post is HeatScale; Heatscale is used everywhere that involves SOME kind of Thermal Energy <-> Electrical Energy conversion. Such as Thermomachines, TEG, Turbine, etc. But the way this is used is inconsistent.
For Thermomachines, it means that the flat, fixed amount of cooling they apply is 8 times more effective than it normally would be - which means thermomachines technically break the law of conservation by a factor of 8 (at least heaters do - Freezers already break it by virtue of deleting energy outright).
For TEG, however, it means that a mixture gas that holds X amount of energy only produces X/8 amount of electricity when that energy is converted. So if you burn gas such that it produces 8 Megawatts, the TEG will only produce 1 Megawatt; the other 7 is deleted.
Setting aside why Thermomachines use it, the TEG uses it because Tritium fires used to produce obscene amounts of heat. Heat way, way, way beyond what a real tritium fire would actually produce. I won't bore you with the math, but the summary is that because ancient atmosians wanted fat maxcaps - they had it changed such that each mol of Tritium burned would result in just under 30Mj of heat (distributed across 10 mols of water vapor; which was also a mass conservation break). NOW Tritium produces 3 megajoules per mol burned (across 1 mol of vapor; which results in the temperature & pressure shift being the same); which is 10x less (and also still 10x more than "real" tritium would produce).
Which means TEGs which could previously produce 15 Megawatts now barely do 1.5. Even with a theoretically perfect, multi-chamber (or multi-pipe) setup you can still only get barely 10 megawatts out of the TEG and those setups tend to take nearly the entire round to create. A simple, one-chamber TEG can never do more than 3 at the absolute most.
Now to the uninitiated, 3 megawatts sounds like alot of power. Afterall most stations need only 300-600kw to keep the lights on. It is easier to consider the comparison to other engines
Tesla - Can produce 625kw by itself as just a lightning ball, with close to 0 setup. When time is actually given to create an optimized setup it does 2MW out of the gate and scales up to a maximum of 40MW
Singularity - Requires almost 0 setup, and by simply producing and cooling Tritium with some freezers can be amplified to 10MW+. Currently suffering from a similar bug that is quartering (rather than eighth-ing) its power output.
SuperMatter - Like Singu, except anywhere from 2 to 6 times stronger, requiring about the same amount of setup as a TEG
Reactor - Easily produces 10MW+ with close to zero effort beyond sourcing raw materials
Turbine - Objectively superior TEG whose only limitation is a hardcap on its power output at 10 Megawatts; the same as a perfectly optimized TEG for a fraction of the effort and far less complexity. The 10mw limitation will also be going away with the move to Forky; meaning once we go to forky there is 0 reason to ever use a TEG. It may as well be removed from the game.
Thus, due to an ancient decision entirely unrelated to the TEG (support the creation and usage of maxcaps) and an oversight when a fix to that ancient decision was deployed, the TEG is now currently 8 times weaker than it should be and not at all worth using compared to the other engines when the effort required to use it is taken into account.
